Quattro has an ad serving, tracking and analytics platform to help advertisers engage with mobile consumers. Its Q Elevation platform can be used to target ad campaigns based on consumer demographics, location, time of day and other factors.

"We are thrilled to let you know that Apple has acquired Quattro," said the blog post, signed by Andy Miller, Apple's vice president of mobile advertising. "For now, the offerings and services you receive from Quattro Wireless will not change."

Miller's blog entry did not give details on the acquisition. On Monday, the Wall Street Journal blog All Things Digital reported Apple planned to pay $275 million for Quattro. Representatives of Apple and Quattro could not immediately be reached.

Mobile advertising is considered a hot market because of the potential to reach consumers on devices that they carry with them everywhere and personalize. Observers see the market for mobile advertising as relatively untapped, with effective approaches just beginning to take shape. Apple could use an advertising platform to generate more revenue from the iPhone, and potentially from the tablet computer it is rumored to be developing.

Google, a rival to Apple in the mobile arena, made its own move into mobile advertising in November when it agreed to acquire AdMob for $750 million. That proposed deal is being investigated by U.S. antitrust regulators, and two consumer groups have called on the government to block it.

Quattro is based in Waltham, Mass. Its clients include Ford Motor, Procter & Gamble, Walt Disney and Visa. Its network partners include Time, Gawker, Univision and CBS Interactive, according to the company's Web site.